Network coexistence is achieved relatively easily when networks communicate with each other, but when the networks do not communicate with each other, network coexistence is restricted since there is no information about an adjacent network. Specifically, since there is no information about a channel that is used by the adjacent network, transmission power is minimized so as to reduce interference. However, in this case, terminals at the edge of a cell may fail to communicate. Also, for a terminal having a low reception signal to noise ratio (SNR) to communicate, the terminal must move to within a communicatable range and then turn on again, since another terminal in an existing network cannot increase transmission power because the existence of a predetermined terminal is not known.
The networks must communicate with each other for network coexistence, but in a home network, due to security, the network coexistence must be possible without communication between the networks. Also, a terminal which is turned on in a low reception SNR area is unable to receive a header or a beacon from an existing network, and thus is unable to connect to the existing network.